/Engine/Plugins/Runtime/RigVM/Source/RigVMDeveloper/Public/RigVMModel/RigVMGraph.h
Returns the modified event, which can be used to subscribe to changes happening within the Graph.
[FRigVMGraphModifiedEvent](API\Plugins\RigVMDeveloper\RigVMModel\FRigVMGraphModifiedEvent) & OnModified()